Method and apparatus for identifying in-call capability features

ABSTRACT

A method and apparatus are provided for identifying In-Call capability features. The method includes sending, by a Mobile Originated (MO), a call request message to a Mobile Terminated (MT), wherein the call request message comprises information regarding In-Call capability features of the MO; receiving, by the MO, a call response message from the MT, wherein the call response message comprises information regarding In-Call capability features of the MT; and performing, by the MO, In-Call capability negotiation with the MT.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a 371 of International Application No. PCT/KR2019/007079 filed on Jun. 12, 2019, which claims priority to India Patent Application No. 201841021986 filed on Jun. 12, 2018, and India Patent Application No. 201841021986 filed on Jun. 10, 2019, the disclosures of which are herein incorporated by reference in their entirety.

BACKGROUND 1. Field

The disclosure relates to mobile communication, and more specifically to a method and apparatus for identifying In-Call capability features.

2. Description of Related Art

Conventionally, a Mobile Originated (MO) has to negotiate with a Mobile Terminated (MT) after establishing a call between the MO and the MT , to know In-Call capability features of the MT such as a shared sketch, a shared map etc.

Due to various timing issue in signalling the In-Call capability features of the MO and the MT after establishing the call, the MO and the MT do not properly display the call and the In-Call capabilities to the user. In case of a communication between the MO and the MT in a slow network, the SIP messages may be jumbled up. Therefore, the MO and the MT receives the SIP messages totally in a non-sequential manner, which further leads the MO and the MT to operate in an un-predictable manner. Therefore, signalling of a large amount of SIP messages for every call session is unfavourable for identifying the In-Call capability features of the MO and the MT . Moreover, signalling of the large amount of SIP messages consumes network traffic in large amount.

In case of a SUBSCRIBE, PUBLISH, AND NOTIFY capability exchange network, the In-Call capability features are not defined by Mobile Communications Association (GSMA). However, communicating the In-Call capability features of the MO and the MT is desirable in the SUBSCRIBE, PUBLISH, AND NOTIFY capability exchange network.

In hybrid networks, the MO supports a PRESENCE way of capability discovery and the MT supports OPTIONS way of capability discovery and vice versa. Conventional methods does not define steps for handling the signalling messages in the hybrid networks for capability discovery of the MO and the MT due to complexity in using the PRESENCE way and the OPTIONS way together for the capability discovery.

Thus, it is desired to address the above mentioned shortcomings or at least provide a useful alternative.

SUMMARY

The embodiments herein is to provide a method and apparatus for identifying In-Call capability features without dedicated capability discovery procedure.

The embodiments provide an efficient method for identifying In-Call capability features in a communication system.

BRIEF DESCRIPTION OF THE DRAWINGS

This method and apparatus is illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:

FIG. 1A is a sequential diagram illustrating signalling of SIP messages between a MO and a MT to identify In-Call capability features by performing dedicated capability discovery procedure.

FIG. 1B is a sequential diagram illustrating signalling of the SIP messages between the MO and the MT for holding a call.

FIG. 2A is a block diagram of the MO for identifying the In-Call capability features without dedicated capability discovery procedure, according to an embodiment of the disclosure;

FIG. 2B is a block diagram of the MT for identifying the In-Call capability features without dedicated capability discovery procedure, according to an embodiment of the disclosure;

FIG. 3 is a flow diagram illustrating a method for identifying the In-Call capability features without dedicated capability discovery procedure by the MO, according to an embodiment of the disclosure;

FIG. 4 is a flow diagram illustrating a method for identifying In-Call capability features without dedicated capability discovery procedure by the MT, according to an embodiment of the disclosure;

FIG. 5 is a sequential diagram illustrating signalling of the SIP messages between the MO and the MT to identify the In-Call capability features without dedicated capability discovery procedure, according to an embodiment of the disclosure; and

FIG. 6 is a sequential diagram illustrating signalling of the SIP messages between the MO and the MT for holding the call, according to an embodiment of the disclosure.

DETAILED DESCRIPTION

Accordingly the embodiments herein provide a method for identifying In-Call capability features without dedicated capability discovery procedure. The method may include sending, by a Mobile Originated (MO), a call request message to a Mobile Terminated (MT), wherein the call request message comprises information regarding In-Call capability features of the MO; receiving, by the MO, a call response message from the MT, wherein the call response message comprises information regarding In-Call capability features of the MT; and performing, by the MO, In-Call capability negotiation with the MT.

In an embodiment, the call request message may be a Session Initiation Protocol (SIP) INVITE message and the call response message may be a SIP INVITE 200 OK message.

In an embodiment, the information regarding In-Call capability features of the MO may be included in a contact header of the call request message when the MO supports a Voice Over Long Term Evolution (VOLTE) and a Rich Communication Service (RCS) on a single Packet Data Network (PDN) and the MT supports the VOLTE and the RCS on a single PDN.

In an embodiment, the information regarding In-Call capability features of the MO may be included in a SIP private extension header of the call request message when one of: a. The MO supports a VOLTE and a RCS on a single PDN, and the MT supports the VOLTE on a first PDN and the RCS on a second PDN, b. The MO supports the VOLTE on the first PDN and the RCS on the second PDN, and the MT supports the VOLTE and the RCS on the single PDN, and c. The MO supports the VOLTE on the first PDN and the RCS on the second PDN, and the MT supports the VOLTE on the first PDN and the RCS on the second PDN.

In an embodiment, the method may be performed in a SUBSCRIBE, PUBLISH, AND NOTIFY network, a network that supports OPTIONS way of capability exchange or a hybrid network.

Accordingly the embodiments herein provide a method for identifying In-Call capability features without dedicated capability discovery procedure. The method may include receiving, by a Mobile Terminated (MT), a call request message from a Mobile Originated (MO), wherein the call request message comprises information regarding In-Call capability features of the MO; sending, by the MT, a call response message comprising information regarding In-Call capability features of the MT to the MO, when the MT is a Voice Over Long Term Evolution (VOLTE) device, or performing, by the MT, a legacy capability exchange for exchanging the information regarding In-Call capability features of the MT, when the MT is a non-VOLTE device.

In an embodiment, wherein sending of, by the MT, the call response message comprises: determining, by the MT, whether the information regarding In-Call capability features of the MO is included in a contact header of the call request message; determining, by the MT, whether the information regarding In-Call capability features of the MO is included in a SIP private extension header of the call request message, in response to determining that the information regarding In-Call capability features of the MO is not included in the contact header of the call request message; and sending, by the MT, the call response message comprising the information regarding In-Call capability features of the MT to the MO.

In an embodiment, the call request message may be a Session Initiation Protocol (SIP) INVITE message and the call response message is a SIP INVITE 200 OK message.

In an embodiment, the information regarding In-Call capability features of the MO may be included in the contact header of the call request message when the MO supports a VOLTE and a Rich Communication Service (RCS) on a single Packet Data Network (PDN) and the MT supports the VOLTE and the RCS on a single PDN.

In an embodiment, wherein the information regarding In-Call capability features may be included in the SIP private extension header of the call request message when one of: a. The MO supports a VOLTE and a RCS on a single PDN, and the MT supports the VOLTE on a first PDN and the RCS on a second PDN, b. The MO supports the VOLTE on the first PDN and the RCS on the second PDN, and the MT supports the VOLTE and the RCS on the single PDN, and c. The MO supports the VOLTE on the first PDN and the RCS on the second PDN, and the MT supports the VOLTE on the first PDN and the RCS on the second PDN.

In an embodiment, the method may be performed in a SUBSCRIBE, PUBLISH, AND NOTIFY network, a network that supports OPTIONS way of capability exchange or a hybrid network.

Accordingly the embodiments herein provide a MO for identifying In-Call capability features without dedicated capability discovery procedure. The MO may include a memory; and a processor, coupled to the memory, configured to: send a call request message to a Mobile Terminated (MT), wherein the call request message comprises information regarding In-Call capability features of the MO; receive a call response message from the MT, wherein the call response message comprises information regarding In-Call capability features of the MT; and perform In-Call capability negotiation with the MT.

In an embodiment, the call request message may be a Session Initiation Protocol (SIP) INVITE message and the call response message is a SIP INVITE 200 OK message.

In an embodiment, the information regarding In-Call capability features of the MO may be included in a contact header of the call request message when the MO supports a Voice Over Long Term Evolution (VOLTE) and a Rich Communication Service (RCS) on a single Packet Data Network (PDN) and the MT supports the VOLTE and the RCS on a single PDN.

Accordingly the embodiments herein provide a MT for identifying In-Call capability features without dedicated capability discovery procedure. The MT may include a memory; and a processor, coupled to the memory, configured to: receive a call request message from a Mobile Originated (MO), wherein the call request message comprises information regarding In-Call capability features of the MO; send a call response message comprises information regarding In-Call capability features of the MT, when the MT is a Voice Over Long Term Evolution (VOLTE) device or perform a legacy capability exchange for exchanging the information regarding In-Call capability features of the MT, when the MT is a non-VOLTE device.

These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. Also, the various embodiments described herein are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments. The term “or” as used herein, refers to a non-exclusive or, unless otherwise indicated. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein can be practiced and to further enable those skilled in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

As is traditional in the field, embodiments may be described and illustrated in terms of blocks which carry out a described function or functions. These blocks, which may be referred to herein as managers, units, modules, hardware components or the like, are physically implemented by analog and/or digital circuits such as logic gates, integrated circuits, microprocessors, microcontrollers, memory circuits, passive electronic components, active electronic components, optical components, hardwired circuits and the like, and may optionally be driven by firmware and software. The circuits may, for example, be embodied in one or more semiconductor chips, or on substrate supports such as printed circuit boards and the like. The circuits constituting a block may be implemented by dedicated hardware, or by a processor (e.g., one or more programmed microprocessors and associated circuitry), or by a combination of dedicated hardware to perform some functions of the block and a processor to perform other functions of the block. Each block of the embodiments may be physically separated into two or more interacting and discrete blocks without departing from the scope of the disclosure. Likewise, the blocks of the embodiments may be physically combined into more complex blocks without departing from the scope of the disclosure.

The embodiments herein provide a method for identifying In-Call capability features without dedicated capability discovery procedure. The method includes sending, by a MO (Mobile Originated), a call request message to a MT (Mobile Terminated). Further, the call request message includes the In-Call capability features of the MO. Further, the method includes receiving, by the MO, a call response message from the MT, Further, the call response message includes the In-Call capability features of the MT. Further, the method includes performing, by the MO, In-Call capability negotiation with the MT.

Unlike exiting methods and systems, the proposed method can be used to exchange the In-Call capability features between the MO and the MT within less number of signaling messages. Therefore, a jumbling up of SIP (Session Initiation Protocol) messages in a slow network can be avoid by employing the proposed method in the slow network, due to exchanging reduced number of signaling messages.

Based on the proposed method, the MO and the MT exchanges the In-Call capability features while establishing a call. Therefore, a timing issue in signalling the In-Call capability features of the MO and the MT after establishing the call in the existing system can be solved by employing the proposed method.

An established call between the MO and the MT can hold and resume by sending less number of signaling messages between the MO and the MT based on the proposed method. Therefore, the MO and the MT consumes only a less amount of network traffic for exchanging the In-Call capability features, holding and resuming the call etc., while comparing to the existing methods and systems. The proposed method also have a flexibility to employ in a SUBSCRIBE, PUBLISH, AND NOTIFY capability exchange network, a network that supports OPTIONS way of capability exchange as well as in hybrid networks for exchanging the In-Call capability features of the MO and the MT.

That is, the MO and the MT in a SUBSCRIBE, PUBLISH, AND NOTIFY capability exchange network, in a network that supports OPTIONS way of capability exchange or in a hybrid network performs an proposed method of the disclosure. In other words, the proposed method disclosed herein may be performed in a SUBSCRIBE, PUBLISH, AND NOTIFY network, a network that supports OPTIONS way of capability exchange or a hybrid network.

Furthermore the identification of the In-Call capability features without dedicated capability discovery procedure is used in a SUBSCRIBE, PUBLISH, AND NOTIFY network, a network that supports OPTIONS way of capability exchange and a hybrid network, according to the present disclosure.

Furthermore, the In-Call capability features are identifying without performing a dedicated capability discovery procedure, according to the present disclosure.

According to the present disclosure, In-Call capability features may be information regarding In-Call capability features. Furthermore, the information regarding In-Call capability may include information regarding whether the MO or the MT is capable of sharing content (such as map, sketch, presentation, chat, location, video, audio, files or group of files), but not limited thereon. Furthermore, In-Call capability features may includes Pre-call capability and Post-call capability.

Referring now to the drawings, and more particularly to FIGS. 1A through 6, there are shown preferred embodiments.

A MO 10 and a MO 100 are similar devices which operate as a mobile originated, whereas the MO 100 may include novel hardware elements which describe in the embodiments of the disclosure. A MT 20 and a MT 200 are similar devices which operate as a mobile terminated, whereas the MT 200 may include novel hardware elements which describe in the embodiments of the disclosure.

The MO 10, MO 100, MT 20, and MT 200 can be, for example, but not limited to a cellular phone, a smart phone, a Personal Digital Assistant (PDA), a tablet computer, a laptop computer, a smart social robot, a smart watch, a music player, a video player, an Internet of things (IoT) device or the like.

FIG. 1A is a sequential diagram illustrating signalling of Session Initiation Protocol (SIP) messages between the MO 10 and the MT 20 to identify the In-Call capability features by performing OPTIONS way of capability discovery.

In operation A101, the MO 10 may send a call request message (i.e. INVITE message) to the MT 20 for connecting to the MT 20. In operation A102, the MT 20 may send a call response message (i.e. 200 OK message), in response to connecting to the MO 10.

In operation A103, the MO 10 may send an acknowledgment to the MT 20, in response to receiving the call response message. In operation A104, the MO 10 may send OPTIONS message to the MT 20 for indicating the In-Call capability features of the MO 10 to the MT 20, where a contact header of the OPTIONS message may include the In-Call capability features of the MO 10.

In operation A105, the MT 20 may acknowledge with the 200 OK message to the MO 10, in response to receiving the OPTIONS message from the MO 10. In operation A106, the MT 20 may send OPTIONS message to the MO 10 for indicating the In-Call capability features of the MT 20 to the MO 10, where the contact header of the OPTIONS message may include the In-Call capability features of the MT 20.

In operation A107, the MO 10 may acknowledge with the 200 OK message to the MT 20, in response to receiving the OPTIONS message from the MT 20. Therefore, at least two OPTIONS messages are consumed for each connected call, to know the In-Call capability features of the MO 10 and the MT 20.

FIG. 1B is a sequential diagram illustrating signalling of the SIP messages between the MO 10 and the MT 20 for holding the connected call.

The MO 10 has to negotiate with the MT 20 to hold/resume a connected call. In operation B101, the MO 10 may send the call request message (i.e. INVITE message) to the MT 20 for connecting to the MT 20. In operation B102, the MT 20 may send the call response message (i.e. 200 OK message), in response to connecting to the MO 10.

In operation B103, the MO 10 may send the acknowledgment to the MT 20, in response to receiving the call response message. In operation B104, the MO 10 may send OPTIONS message to the MT 20, indicating that the MO 10 wants to hold the connected call, where the contact header of the OPTIONS message may not include the In-Call capability features of the MO 10.

In operation B105, the MT 20 may acknowledge with the 200 OK message to the MO 10, in response to receiving the OPTIONS message from the MO 10. In operation B106, the MT 20 may send OPTIONS message to the MO 10, indicating that the MO 10 is ready to hold the connected call, where the contact header of the OPTIONS message may not include the In-Call capability features of the MT 20.

In operation B107, the MO 10 may acknowledge with the 200 OK message to the MT 20, in response to receiving the OPTIONS message from the MT 20. Therefore, at least two OPTIONS messages are consumed for each connected call, to hold the call. Also, similar number of steps as mentioned for holding the call is required to resume the call.

FIG. 2A is a block diagram of the MO 100 for identifying In-Call capability features without dedicated capability discovery procedure, according to an embodiment of the disclosure.

Examples for the MO 100 are, but not limited to a smart phone, a tablet computer, a personal computer, a personal digital assistance (PDA), an Internet of Things (IoT) or the like. In an embodiment, the MO 100 may include, but not limited to a processor 110, a memory 120 and a communicator 130. In an embodiment, the processor 110 may include an In-Call capability message indicator 112 and an In-Call capability negotiator 114. The processor 110 may be coupled to the memory 120 and the communicator 130. The processor 110 may be configured to send a call request message to the MT 200. The call request message may include the In-Call capability features of the MO 100. That is, information regarding In-Call capability features of the MO may be included in the call request message.

In an embodiment, the call request message may a SIP INVITE message (also called as an INVITE message). An example for the SIP INVITE message based on proposed solution is given below, but not limited to thereon:

To: <sip:+918618796051@ims.mnc861.mcc405.3gppnetwork.org;user=phone>

From: <tel:+918618796032>;tag=82b79c35

CSeq: 1 INVITE

Session-Expires: 1800

Min-SE: 90

Contact: <sip:405861060003397@[2405:204:5e00:ced7::81b:30b0]:5060>; sip.instance=“<urn:gsma:imei:35241909-031555 0>”;q=1.0;+g.3gpp.icsi-ref=“urn%3Aurn-7%3A3gpp service.ims.icsi.mmtel,urn%3Aurn-7%3A3gpp service.ims.icsi.gsma.callcomposer,urn%3Aurn-7%3A3gpp-service.ims.icsi.gsma.sharedmap,urn%3Aurn-7%3A3gpp-service.ims.icsi.gsma.sharedsketch,urn%3Aurn-7%3A3gpp-service.ims.icsi.gsma.callunanswered”;video;+g.oma.sip-im;+g.3gpp.smsip;+g.3gpp.iari-ref=“urn%3Aurn-7%3A3gpp-application.ims.rcse.im,urn%3Aurn-7%3A3gpp-application.ims.iari.rcs.fullsfgroupchaturn%3Aurn-7%3A3gpp-application.ims.iari.rcse.ft,urn%3Aurn-7%3A3gpp-application.ims.iari.rcs.fthttp,urn%3Aurn-7%3A3gpp-application.ims.iari.rcs.ftthumb,urn%3Aurn-7%3A3gpp-application.ims.iari.gsma-is,urn%3Aurn-7%3A3gpp-application.ims.joyn.intmsg,urn%3Aurn-7%3A3gpp-application.ims.iari.rcs.geopush”

Accept: application/sdp

Allow: INVITE, ACK, OPTIONS, CANCEL, BYE, UPDATE, INFO, REFER, NOTIFY, MESSAGE, PRACK

Content-Type: multipart/mixed;boundary=ca2c5e7adb09165e

Supported: timer, sec-agree

User-Agent: Samsung_SM-G960F_G960FXXE1BRD3_IMS_6.0

P-Preferred-Identity: <tel:+918618796032>

Accept-Contact: *;+g.oma.sip-im

In an embodiment. the processor 110 may send the call request message to the MT 200. The In-Call capability message indicator 112 may send the call request message to the MT 200. The processor 110 may be configured to receive a call response message from the MT 200. The call response message may include the In-Call capability features of the MT 200. In other words, information regarding In-Call capability features of the MT may be included in the call response message.

In an embodiment, the call response message may a SIP INVITE 200 OK message (also called as a 200 OK message). An example for the SIP INVITE 200 OK message based on the proposed solution is given below, but not limited to thereon:

Via: SIP/2.0/TCP [2405:204:5c89:419::172f:f0a0]:6100;branch=z9hG4bK-524287-1---

Contact: <sip:20724442698782839-

68330@ka1wcas0019rcs.ims.mnc861.mcc405.3gppnetwork.org:5060;fid=server_1>;+sip.instance=“<urn:gsma:imei:35241909-008267-0>”;+g.3gpp.icsi-ref=“urn%3Aurn-7%3A3gpp-service.ims.icsi.mmtel,urn%3Aurn-7%3A3gpp-service.ims.icsi.gsma.callcomposer,urn%3Aurn-7%3A3gpp-service.ims.icsi.gsma.sharedmap,urn%3Aurn-7%3A3gpp-service.ims.icsi.gsma.sharedsketch,urn%3Aurn-7%3A3gpp-service.ims.icsi.gsma.callunanswered”;+g.oma.sip-im;+g.3gpp.smsip;+g.3gpp.iari-ref=“urn%3Aurn-7%3A3gpp-application.ims.iari.rcse.im,urn%3Aurn-7%3A3gpp-application.ims.iari.rcs.fullsfgroupchaturn%3Aurn-7%3A3gpp-application.ims.iari.rcse.ft,urn%3Aurn-7%3A3gpp-application.ims.iari.rcs.fthttp,urn%3Aurn-7%3A3gpp-application.ims.iari.rcs.ftthumb,urn%3Aurn-7%3A3gpp-application.ims.iari.gsma-is,urn%3Aurn-7%3A3gpp-application.ims.joyn.intmsg,urn%3Aurn-7%3A3gpp-application.ims.iariscs.geopush”;video

To: <sip:+916361752915@ims.mnc861.mcc405.3gppnetwork.org;user=phone>;tag=j fs1h7dv-4z613v

From: <tel:+916361752913>;tag=98956326

Call-ID: 0sDiHD7RI_Lzgwj-vzrizg..@2405:204:5c89:419::172f:f0a0

CSeq: 1 INVITE

Session-Expires: 1800;refresher=uac

Content-Type: application/sdp

Server: IM-serv/OMA1.0 WCAS

Content-Length: 442

In an embodiment. the processor 110 may receive the call response message from the MT 200. In an embodiment, the In-Call capability message indicator 112 may receive the call response message from the MT 200. The processor 110 may be configured to perform the In-Call capability negotiation with the MT 200. In an embodiment, the In-Call capability negotiator 114 may perform the In-Call capability negotiation with the MT 200.

In an embodiment, the MO 100 may indicate the In-Call capability features in a contact header of the call request message when the MO 100 supports a VOLTE (Voice Over Long Term Evolution) and a RCS (Rich Communication Suite) on a single PDN (Packet Data Network) and the MT 200 support the VOLTE and the RCS on a single PDN.

Furthermore, In an embodiment, the MO 100 may indicate the In-Call capability features in a SIP private extension header of the call request message when the MO 100 supports the VOLTE and the RCS on the single PDN, and the MT 200 supports the VOLTE on a first PDN and the RCS on a second PDN.

Furthermore, In an embodiment, the MO 100 may indicate the In-Call capability features in the SIP private extension header of the call request message when the MO 100 supports the VOLTE on the first PDN and the RCS on the second PDN, and the MT 200 supports the VOLTE and the RCS on the single PDN.

Additionally, In an embodiment, the MO 100 may indicate the In-Call capability features in the SIP private extension header of the call request message when the MO 100 supports the VOLTE on the first PDN and the RCS on the second PDN, and the MT 200 supports the VOLTE on the first PDN and the RCS on the second PDN.

*93Additionally, In an embodiment, In-Call capability features of a device may be discovered based on a device registration type, where the device is the MO 100 or the MT 200. The type of device registration can be a single registration or a dual registration.

In an embodiment, in the single registration, the VOLTE and the RCS may be registered on a single PDN for a same International Mobile Subscriber Identity (IMSI) or Mobile Subscriber Integrated Services Digital Network (MSISDN). In the dual registration, the VOLTE and the RCS may be registered on a different PDN for the same IMSI or MSISDN.

In an embodiment, when the MO 100 and the MT 200 have the single registration, then the In-Call capability features may negotiate in the contact header of the SIP INVITE message. In an embodiment, when the MO 100 has the single registration and the MT 200 has the dual registration, then the SIP INVITE message may include the SIP private extension header with the In-Call capability features. In an embodiment, when the MO 100 and the MT 200 have the dual registration, then the SIP INVITE message may include the SIP private extension header with the In-Call capability features.

In an embodiment, the MO 100 may generate the SIP private extension header for identifying the In-Call capability features in the dual registration. The SIP private extension header may include all the In-Call capability features supporting by the MO 100. Further, the MO 100 may add the SIP private extension header in the SIP INVITE message to convey the MT 200 that the MO 100 is RCS registered and supports in the In-Call capability features. If the MT 200 is registered to the RCS, then the MT 200 may parse the SIP private extension header and may add the In-Call capability features of the MT 200 in the same SIP private extension header. Further, the MT 200 may reply the SIP INVITE 200 OK message including the updated SIP private extension header. Further, the device may activate the In-Call capability features based on the request/response for the In-Call capability features.

In an embodiment, the SIP private extension header may be defined as P-Associated-Features. Consider the device may be registered to the RCS & In-Call capability features. While initiating the call, the MO 100 may send the SIP INVITE message to the MT 200 by adding the SIP private extension header “P-Associated-Features” with all the supported “In-Call capability features”. An example for the SIP INVITE message is given below, but not limited to thereon:

[-->] INVITE <sip:+918618796078@ims.mnc861.mcc405.3gppnetwork.org> SIP/2.0 [CSeq: 1 INVITE]

Via: SIP/2.0/TCP [2405:204:5c1d:b1a2::b9c:70a4]:6300;branch=z9hG4bK-524287-1---2be2M4ddae419c;rport;transport=TCP

Max-Forwards: 70

Route: <sip:[2405:200:370:1581::33]:5067;lr>

Proxy-Require: sec-agree

Require: sec-agree

Contact: <sip:+918618796078@[2405:204:5c1d:b1a2::b9c:70a4]:6300>;+sip.instance=“<urn:gsma:imei:35202309-002471-0>”;+g.3gpp.icsi-ref=“urn%3Aurn-7%3A3gpp-service.ims.icsi.mmtel”;video

P-Associated-Features: +g.3gpp.icsi-ref=“urn%3Aurn-7%3A3gpp-service.ims.icsi.gsma.sharedmap,urn%3Aurn-7%3A3gpp-service.ims.icsi.gsma.sharedsketch,urn%3Aurn-7%3A3gpp-service.ims.icsi.gsma.callunanswered”

The MT 200 checks the SIP private extension header and returns “In-Call capability features” of the MT 200 in the SIP INVITE 200 OK message. Along with a session negotiation, the In-Call capability negotiation will also be carried out. An example for the SIP INVITE 200 OK message is given below:

<--200 OK INVITE <sip:+918618796078@ims.mnc861.mcc405.3gppnetwork.org> SIP/2.0 [CSeq: 1 INVITE]

Via: SIP/2.0/TCP

[2405:204:5c1d:b1a2::b9c:70a4]:6300;branch=z9hG4bK-524287-1---2be2M4ddae419c;rport;transport=TCP

Max-Forwards: 70

Route: <sip:[2405:200:370:1581::33]:5067;lr>

Proxy-Require: sec-agree

Require: sec-agree

Contact: <sip:+918618796078@[2405:204:5c1d:b1a2::b9c:70a4]:6300>;+sip.instance=“<urn:gsma:imei:35202309-002471-0>”;+g.3gpp.icsi-ref=“urn%3Aurn-7%3 A3gpp-service.ims.icsi.mmtel”;video

P-Associated-Features: +g.3gpp.icsi-ref=“urn%3Aurn-7%3A3gpp-service.ims.icsi.gsma.sharedmap,urn%3Aurn-7%3A3gpp-service.ims.icsi.gsma.sharedsketch,urn%3Aurn-7%3A3gpp-service.ims.icsi.gsma.callunanswered”

The processor 110 may be configured to execute instructions stored in the memory 120. The memory 120 may include non-volatile storage elements. Examples of such non-volatile storage elements may include magnetic hard discs, optical discs, floppy discs, flash memories, or forms of an Electrically Programmable Memory (EPROM) or an Electrically Erasable and Programmable Memory (EEPROM).

In addition, the memory 120 may be considered a non-transitory storage medium. The term ‘non-transitory’ may indicate that the storage medium is not embodied in a carrier wave or a propagated signal. However, the term ‘non-transitory’ should not be interpreted that the memory 120 is non-movable.

In an embodiment, the memory 120 can be configured to store larger amounts of information than the memory 120.For example, a non-transitory storage medium may store data that can, over time, change (e.g., in Random Access Memory (RAM) or cache), but not limited to thereon.

The communicator 130 may be configured to communicate internally between hardware components in the MO 100. Further, the communicator 130 may be configured to communicate the MO 100 to the MT 200.

In an embodiment, the identification of the In-Call capability features without dedicated capability discovery procedure may be used in a SUBSCRIBE, PUBLISH, AND NOTIFY network, a network that supports OPTIONS way of capability exchange and a hybrid network.

In an embodiment, the MO 100 supports the SUBSCRIBE, PUBLISH, AND NOTIFY way of dedicated capability discovery procedure and the MT 200 supports OPTIONS way of dedicated capability discovery procedure and vice versa, in hybrid networks.

Although the FIG. 2A shows the hardware components of the MO 100 but it is to be understood that other embodiments are not limited thereon. In an embodiment, the MO 100 may include less or more number of components. Further, the labels or names of the components are used only for illustrative purpose and does not limit the scope of the invention. One or more components can be combined together to perform same or substantially similar function for identifying the In-Call capability features without dedicated capability discovery procedure.

FIG. 2B is a block diagram of the MT 200 for identifying the In-Call capability features without dedicated capability discovery procedure, according to an embodiment of the disclosure.

Examples for the MT 100 are, but not limited to a smart phone, a tablet computer, a personal computer, a personal digital assistance (PDA), an Internet of Things (IoT) or the like. In an embodiment, the MT 200 may include, but not limited to a processor 210, a memory 220 and a communicator 230. In an embodiment, the processor 210 may include an In-Call capability message indicator 212.

In an embodiment, the processor 210 may be configured to receive the call request message from the MO 100. The In-Call capability message indicator 212 may receive the call request message from the MO 100. The processor 210 may be configured to determine whether the MT 200 is a VOLTE device or a non-VOLTE device.

In an embodiment, determining whether the MT is the VOLTE device or the non-VOLTE device may include determining whether the In-Call capability features of the MO 100 is indicated in the contact header of the call request message. That is, information regarding In-Call capability features of the MO may be included in the contact header of the call request message.

Further, determining whether the MT is the VOLTE device or the non-VOLTE device may include determining whether the In-Call capability features of the MO 100 is indicated in the SIP private extension header of the call request message, in response to determining that the In-Call capability features of the MO is not indicated in the contact header of the call request message. That is, information regarding In-Call capability features of the MO may be included in the SIP private extension header of the call request message.

In an embodiment, the processor 210 may determines whether the MT 200 is the VOLTE device or non-VOLTE device. The In-Call capability message indicator 212 may determine whether the MT 200 is the VOLTE device or the non-VOLTE device.

In an embodiment, the processor 210 may be configured to send the call response message including the In-Call capability features of the MT 200 to the MO 100, in response to determining that the MT 200 is the VOLTE device. In an embodiment, the In-Call capability message indicator 212 may send the call response message to the MO 100, in response to determining that the MT 200 is the VOLTE device.

In an embodiment, the processor 210 may be configured to follow a legacy capability exchange including the In-Call capability features, in response to determining that the MT 200 is the non-VOLTE device. That is, the processor 210 may perform a legacy capability exchange for exchanging the information regarding In-Call capability features, when the MT is a non-VOLTE device.

In an embodiment, The In-Call capability message indicator 212 may follow the legacy capability exchange including the In-Call capability features, in response to determining that the MT 200 is the non-VOLTE device.

In an embodiment, the MT 200 may refer the contact header to know whether the MO 100 supports the In-Call capability features. If the In-Call capability features are not present in the contact header then the MT 200 may check the SIP private extension header. In an embodiment, when the MT 200 is the VOLTE device and does not support In-Call capability features, then the MT 200 may mark the SIP private extension header with value “none” and may send to the MO 100 for avoiding falling back to legacy mode.

In an embodiment, the processor 210 may be configured to execute instructions stored in the memory 220. The memory 220 may include non-volatile storage elements. Examples of such non-volatile storage elements may include magnetic hard discs, optical discs, floppy discs, flash memories, or forms of an Electrically Programmable Memory (EPROM) or an Electrically Erasable and Programmable Memory (EEPROM).

In addition, the memory 220 may be considered a non-transitory storage medium. The term ‘non-transitory’ may indicate that the storage medium is not embodied in a carrier wave or a propagated signal. However, the term ‘non-transitory’ should not be interpreted that the memory 220 is non-movable.

In an embodiment, the memory 220 can be configured to store larger amounts of information than the memory 220. In For example, a non-transitory storage medium may store data that can, over time, change (e.g., in Random Access Memory (RAM) or cache) , but not limited to thereon.

The communicator 230 may be configured to communicate internally between hardware components in the MT 200. Further, the communicator 230 may be configured to communicate the MT 200 to the MO 100.

Although the FIG. 2B shows the hardware components of the MT 200 but it is to be understood that other embodiments are not limited thereon. In an embodiment, the MT 200 may include less or more number of components. Further, the labels or names of the components are used only for illustrative purpose and does not limit the scope of the invention. One or more components can be combined together to perform same or substantially similar function for identifying the In-Call capability features without dedicated capability discovery procedure.

FIG. 3 is a flow diagram 300 illustrating a method for identifying the In-Call capability features without dedicated capability discovery procedure by the MO 100, according to an embodiment of the disclosure.

In operation 301, the method may include sending the call request message to the MT 200, wherein the call request message may include the In-Call capability features of the MO 100. In an embodiment, the method may allow the In-Call capability message indicator 112 to send the call request message to the MT 200, wherein the call request message may include the In-Call capability features of the MO 100.

In operation 302, the method may include receiving the call response message from the MT 200, wherein the call response message may include the In-Call capability features of the MT 200. In an embodiment, the method may allow the In-Call capability message indicator 112 to receive the call response message from the MT 200, where the call response message may include the In-Call capability features of the MT 200.

In operation 303, the method may include performing the In-Call capability negotiation with the MT 200. In an embodiment, the method may allow the In-Call capability negotiator 114 to perform the In-Call capability negotiation with the MT 200.

The various actions, acts, blocks, steps, or the like in the flow diagram 300 may be performed in the order presented, in a different order or simultaneously. Further, in some embodiments, some of the actions, acts, blocks, steps, or the like listed in FIG. 3 may be omitted, added, modified, skipped, or the like without departing from the scope of the invention.

FIG. 4 is a flow diagram 400 illustrating a method for identifying the In-Call capability features without dedicated capability discovery procedure by the MT 200, according to an embodiment of the disclosure.

In operation 401, the method may include receiving the call request message from the MO 100, wherein the call request message may include the In-Call capability features of the MO 100. In an embodiment, the method may allow the In-Call capability message indicator 212 to receive the call request message from the MO 100, where the call request message may include the In-Call capability features of the MO 100.

In operation 402, the method may include determining whether the MT 200 is one of the VOLTE device and the non-VOLTE device. In an embodiment, the method may allow the In-Call capability message indicator 212 to determine whether the MT 200 is one of the VOLTE device and the non-VOLTE device.

In operation 403, the method may include sending the call response message including the In-Call capability features of the MT 200 to the MO 100, in response to determining that the MT 200 is the VOLTE device. In an embodiment, the method may allow the In-Call capability message indicator 212 to send the call response message including the In-Call capability features of the MT 200 to the MO 100, in response to determining that the MT 200 is the VOLTE device.

In operation 404, the method may include following the legacy capability exchange including the In-Call capability features, in response to determining that the MT 200 is the non-VOLTE device. In an embodiment, the method may allow the In-Call capability message indicator 212 to follow the legacy capability exchange including the In-Call capability features, in response to determining that the MT 200 is the non-VOLTE device.

The various actions, acts, blocks, steps, or the like in the flow diagram 400 may be performed in the order presented, in a different order or simultaneously. Further, in some embodiments, some of the actions, acts, blocks, steps, or the like listed in FIG. 4 may be omitted, added, modified, skipped, or the like without departing from the scope of the invention.

FIG. 5 is a sequential diagram illustrating signalling of the SIP messages between the MO 100 and the MT 200 to identify the In-Call capability features without dedicated capability discovery procedure, according to an embodiment of the disclosure.

In operation 501, the MO 100 may send the INVITE message to the MT 200 for connecting to the MT 200 and indicating the In-Call capability features of the MO 100. The contact header and the SIP private extension header of the INVITE message may include the In-Call capability features.

In operation 502, the MT 200 may send the 200 OK message to the MO 100 for acknowledging the received INVITE message and indicating the In-Call capability features of the MT 200. The contact header and the SIP private extension header of the 200 OK message may include the In-Call capability features of the MT 200.

In operation 503, the MO may to send acknowledge to the MT, in response to receiving the 200 OK message.

FIG. 6 is a sequential diagram illustrating signalling of the SIP messages between the MO 100 and MT 200 for holding a call during a call session, according to an embodiment of the disclosure.

Consider, the MO 100 is connected to the MT 200 for a call session. The MO 100 may remove the In-Call capability features in the contact header and the SIP private extension header of the INVITE message and may mark as ‘none’.

In operation 601, the MO 100 may send the INVITE message to the MT 200 for holding the call. In response to receiving the INVITE message, the MT 200 may remove the In-Call capability features in the contact header and the SIP private extension header of the 200 OK message and may mark as ‘none’.

In operation 602, the MT 200 may send the 200 OK message to the MO 100, indicating that the MT 100 is ready to hold the call.

In operation 603, the MO 100 may to send acknowledge to the MT 200 and holds the call, in response to receiving the 200 OK message. Similarly, the call on hold can be resume by signalling between the MO 100 and MT 200 based on the proposed method.

The embodiments disclosed herein can be implemented using at least one software program running on at least one hardware device and performing network management functions to control the elements. The elements shown in FIGS. 2A and 2B can be at least one of a hardware device, or a combination of hardware device and software module.

The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein. 

1. A method of identifying In-Call capability features, comprising: sending, by a Mobile Originated (MO), a call request message to a Mobile Terminated (MT), wherein the call request message comprises information regarding In-Call capability features of the MO; receiving, by the MO, a call response message from the MT, wherein the call response message comprises information regarding In-Call capability features of the MT; and performing, by the MO, In-Call capability negotiation with the MT.
 2. The method of claim 1, wherein the call request message is a Session Initiation Protocol (SIP) INVITE message and the call response message is a SIP INVITE 200 OK message.
 3. The method of claim 1, wherein the information regarding In-Call capability features of the MO included in a contact header of the call request message when the MO supports a Voice Over Long Term Evolution (VOLTE) and a Rich Communication Service (RCS) on a single Packet Data Network (PDN) and the MT supports the VOLTE and the RCS on a single PDN.
 4. The method of claim 1, wherein the information regarding In-Call capability features of the MO included in a SIP private extension header of the call request message when one of: a. The MO supports a VOLTE and a RCS on a single PDN, and the MT supports the VOLTE on a first PDN and the RCS on a second PDN, b. The MO supports the VOLTE on the first PDN and the RCS on the second PDN, and the MT supports the VOLTE and the RCS on the single PDN, and c. The MO supports the VOLTE on the first PDN and the RCS on the second PDN, and the MT supports the VOLTE on the first PDN and the RCS on the second PDN.
 5. The method of claim 1, wherein the method is performed in a SUBSCRIBE, PUBLISH, AND NOTIFY network, a network that supports OPTIONS way of capability exchange or a hybrid network.
 6. A method of identifying In-Call capability features, comprising: receiving, by a Mobile Terminated (MT), a call request message from a Mobile Originated (MO), wherein the call request message comprises information regarding In-Call capability features of the MO; sending, by the MT, a call response message comprising information regarding In-Call capability features of the MT to the MO, when the MT is a Voice Over Long Term Evolution (VOLTE) device, or performing, by the MT, a legacy capability exchange for exchanging the information regarding In-Call capability features of the MT, when the MT is a non-VOLTE device.
 7. The method of claim 6, wherein sending of, by the MT, the call response message comprises: determining, by the MT, whether the information regarding In-Call capability features of the MO is included in a contact header of the call request message; determining, by the MT, whether the information regarding In-Call capability features of the MO is included in a SIP private extension header of the call request message, in response to determining that the information regarding In-Call capability features of the MO is not included in the contact header of the call request message; and sending, by the MT, the call response message comprising the information regarding In-Call capability features of the MT to the MO.
 8. The method of claim 6, wherein the call request message is a Session Initiation Protocol (SIP) INVITE message and the call response message is a SIP INVITE 200 OK message.
 9. The method of claim 7, wherein the information regarding In-Call capability features included in the contact header of the call request message when the MO supports a VOLTE and a Rich Communication Service (RCS) on a single Packet Data Network (PDN) and the MT supports the VOLTE and the RCS on a single PDN.
 10. The method of claim 7, wherein the information regarding In-Call capability features of the MO included in the SIP private extension header of the call request message when one of: a. The MO supports a VOLTE and a RCS on a single PDN, and the MT supports the VOLTE on a first PDN and the RCS on a second PDN, b. The MO supports the VOLTE on the first PDN and the RCS on the second PDN, and the MT supports the VOLTE and the RCS on the single PDN, and c. The MO supports the VOLTE on the first PDN and the RCS on the second PDN, and the MT supports the VOLTE on the first PDN and the RCS on the second PDN.
 11. The method of claim 6, wherein the method is performed in a SUBSCRIBE, PUBLISH, AND NOTIFY network, a network that supports OPTIONS way of capability exchange or a hybrid network.
 12. A Mobile Originated (MO) for identifying In-Call capability features, the MO comprising: a memory; and a processor, coupled to the memory, configured to: send a call request message to a Mobile Terminated (MT), wherein the call request message comprises information regarding In-Call capability features of the MO; receive a call response message from the MT, wherein the call response message comprises information regarding In-Call capability features of the MT; and perform In-Call capability negotiation with the MT.
 13. The MO of claim 12, wherein the call request message is a Session Initiation Protocol (SIP) INVITE message and the call response message is a SIP INVITE 200 OK message.
 14. The MO of claim 12, wherein the information regarding In-Call capability features of the MO included in a contact header of the call request message when the MO supports a Voice Over Long Term Evolution (VOLTE) and a Rich Communication Service (RCS) on a single Packet Data Network (PDN) and the MT supports the VOLTE and the RCS on a single PDN.
 15. A Mobile Terminated (MT) for identifying In-Call capability features, the MT comprising: a memory; and a processor, coupled to the memory, configured to: receive a call request message from a Mobile Originated (MO), wherein the call request message comprises information regarding In-Call capability features of the MO; send a call response message comprises information regarding In-Call capability features of the MT, when the MT is a Voice Over Long Term Evolution (VOLTE) device or perform a legacy capability exchange for exchanging the information regarding In-Call capability features of the MT, when the MT is a non-VOLTE device. 